package com.czy.basecommon.utils.tools;

import android.os.Build;


import androidx.annotation.RequiresApi;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Base64;

public class Base64Utils {
    /** *//**
     * 文件读取缓冲区大小
     */
    private static final int CACHE_SIZE = 1024;

    /** *//**
     * <p>
     * BASE64字符串解码为二进制数据
     * </p>
     *
     * @param base64
     * @return
     * @throws Exception
     */
    @RequiresApi(api = Build.VERSION_CODES.O)
    public static byte[] decode(String base64) throws Exception {
        //return Base64.decode(base64.getBytes());
        //Base64.getEncoder().encodeToString("在Java 8中,Base64编码已经成为Java类库的标准。".getBytes("utf-8"));
        return Base64.getDecoder().decode(base64);
    }




    /** *//**
     * <p>
     * BASE64字符串解码为二进制数据
     * </p>
     *
     * @param base64
     * @return
     * @throws Exception
     */
    @RequiresApi(api = Build.VERSION_CODES.O)
    public static byte[] decodes(String base64) throws Exception {
        //return Base64.decode(base64.getBytes());
        //Base64.getEncoder().encodeToString("在Java 8中,Base64编码已经成为Java类库的标准。".getBytes("utf-8"));
       return Base64.getMimeDecoder().decode(base64);


    }

    /** *//**
     * <p>
     * 二进制数据编码为BASE64字符串
     * </p>
     *
     * @param bytes
     * @return
     * @throws Exception
     */

    @RequiresApi(api = Build.VERSION_CODES.O)
    public static String encode(byte[] bytes) throws Exception {
        //return new String(Base64.encode(bytes));

        return Base64.getEncoder().encodeToString(bytes);
    }

    /** *//**
     * <p>
     * 将文件编码为BASE64字符串
     * </p>
     * <p>
     * 大文件慎用，可能会导致内存溢出
     * </p>
     *
     * @param filePath 文件绝对路径
     * @return
     * @throws Exception
     */
    @RequiresApi(api = Build.VERSION_CODES.O)
    public static String encodeFile(String filePath) throws Exception {
        byte[] bytes = fileToByte(filePath);
        return encode(bytes);
    }

    /** *//**
     * <p>
     * BASE64字符串转回文件
     * </p>
     *
     * @param filePath 文件绝对路径
     * @param base64 编码字符串
     * @throws Exception
     */
    @RequiresApi(api = Build.VERSION_CODES.O)
    public static void decodeToFile(String filePath, String base64) throws Exception {
        byte[] bytes = decode(base64);
        byteArrayToFile(bytes, filePath);
    }

    /** *//**
     * <p>
     * 文件转换为二进制数组
     * </p>
     *
     * @param filePath 文件路径
     * @return
     * @throws Exception
     */
    public static byte[] fileToByte(String filePath) throws Exception {
        byte[] data = new byte[0];
        File file = new File(filePath);
        if (file.exists()) {
            FileInputStream in = null;
            ByteArrayOutputStream out = null;
            try{
                in = new FileInputStream(file);
                out = new ByteArrayOutputStream(2048);
                byte[] cache = new byte[CACHE_SIZE];
                int nRead = 0;
                while ((nRead = in.read(cache)) != -1) {
                    out.write(cache, 0, nRead);
                    out.flush();
                }
                data = out.toByteArray();
            }catch (Exception e){
                e.printStackTrace();
            }finally {
                if (in != null){
                    in.close();
                }
                if (out != null){
                    out.close();
                }
            }
        }
        return data;
    }

    /** *//**
     * <p>
     * 二进制数据写文件
     * </p>
     *
     * @param bytes 二进制数据
     * @param filePath 文件生成目录
     */
    public static void byteArrayToFile(byte[] bytes, String filePath) throws Exception {
        InputStream in = null;
        OutputStream out = null;
        try{
            in = new ByteArrayInputStream(bytes);
            File destFile = new File(filePath);
            if (!destFile.getParentFile().exists()) {
                destFile.getParentFile().mkdirs();
            }
            destFile.createNewFile();
            out = new FileOutputStream(destFile);
            byte[] cache = new byte[CACHE_SIZE];
            int nRead = 0;
            while ((nRead = in.read(cache)) != -1) {
                out.write(cache, 0, nRead);
                out.flush();
            }
            out.close();
            in.close();
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            if (in != null){
                in.close();
            }
            if (out != null){
                out.close();
            }
        }
    }
}
